Abstract

The authors observed the surface morphology transition from the atomically flat two dimensional layer-by-layer mode to the three dimensional pyramidal mode of heteroepitaxial (PTO) islands synthesized by hydrothermal epitaxy by scanning electron microscopy and atomic force microscopy. Two types of (001) (NSTO) with the same step height, and terrace widths, were used for substrates. They found the critical island thickness at which the growth mode of PTO island was converted and its relation to the terrace width of the substrate. It is suggested that the relaxation of the misfit strain, which originates from out-of-plane lattice mismatch between the PTO island unit cell and the NSTO substrate step or somewhere interior of the film, has an effect on the PTO island growth mode transition.

Received 14 April 2007Accepted 08 August 2007Published online 29 August 2007

Acknowledgments:

This work was supported by the Korea Science and Engineering Foundation (KOSEF) through the National Research Laboratory Program funded by the Ministry of Science and Technology (M10400000024-04J0000-02410).